def count_letter_b(string):
    #TODO: Your code goes here
    a = int(string.count('B'))
    b = int(string.count('b'))
    return a + b

print count_letter_b("Bubble Bungle")

string.upper().count('B')

def count_letter_b(string):
    return sum(map(string.count, 'Bb'))

def countInvariantChars(c,s):
    return s.upper().count(c.upper())



print(countInvariantChars("c","HabloCShaprc"))